Panel: Rocket Fuel Chemical in Water Is Safe
Experts Conclude Higher Perchlorate Levels Not Dangerous to Humans
"There was no real inhibition at this point. It was safe. It did not even invoke a biochemical change," says Richard B. Johnston, Jr., MD, a professor of pediatrics at the University of Colorado School of Medicine and chairman of the committee issuing the report.
Johnston says the committee feels its conclusions are more accurate than those reached by the EPA because the agency has relied too heavily on animal studies that showed adverse health effects at lower doses. Physicians and human toxicologists on the NRC panel were able to more faithfully evaluate studies in humans, he suggests.
"It allowed us to have more confidence in the human data than the EPA did. We did not put as much emphasis, as much confidence, in the animal data," he says.
Environmental groups reacted angrily to the report. The National Resources Defense Council issued a statement late Monday alleging that the NRC panel had been subject to heavy influence from the White House, Defense Department, and companies that make weapons containing perchlorate.
The group also attacked the panel for concluding that pregnant women can ingest the higher level of perchlorate without risking harm to their unborn children, though no studies have addressed the question directly. The report recommends that women in areas with high perchlorate levels in drinking water consider taking iodide supplements to stave off any potential harmful effects of perchlorate on thyroid function in themselves or their offspring.
"It's like exposing pregnant women to cigarette smoke and telling them to wear gas masks," Gina Solomon, MD, the NRDC's senior scientist, says in a statement. "To suggest that part of the solution for pregnant women is to take vitamins to protect their babies from perchlorate exposure is bizarre. It's too little, too late. The burden should be on polluters, not pregnant moms, to protect babies from this toxic chemical."
FDA regulators have also recently suggested that perchlorate may be present in milk and lettuce, opening up the possibility that drinking water may be only one significant source of the chemical.
"This needs to be studied," says Richard Corley, PhD, a staff scientist at the Pacific Northwest National Laboratory in Richland, Wash., and a member of the NRC committee. "I think it's a good idea to start looking at where perchlorate moves."